/****************************************************************************
 *
 * Copyright 2018 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * arch/arm/src/stm32/stm32_exti_alarm.c
 *
 *   Copyright (C) 2009, 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *           Diego Sanchez <dsanchez@nx-engineering.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>
#include <tinyara/irq.h>
#include <tinyara/arch.h>

#include <stdint.h>
#include <stdbool.h>
#include <errno.h>

#include <arch/irq.h>

#include "up_arch.h"
#include "chip.h"
#include "stm32_gpio.h"
#include "stm32_exti.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/* Interrupt handlers attached to the ALARM EXTI */

static xcpt_t stm32_exti_callback;

/****************************************************************************
 * Public Data
 ****************************************************************************/

/****************************************************************************
* Private Functions
****************************************************************************/

/****************************************************************************
 * Name: stm32_exti_alarm_isr
 *
 * Description:
 *   EXTI ALARM interrupt service routine/dispatcher
 *
 ****************************************************************************/

static int stm32_exti_alarm_isr(int irq, void *context)
{
	int ret = OK;

	/* Clear the pending EXTI interrupt */

	putreg32(EXTI_RTC_ALARM, STM32_EXTI_PR);

	/* And dispatch the interrupt to the handler */

	if (stm32_exti_callback) {
		ret = stm32_exti_callback(irq, context);
	}

	return ret;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: stm32_exti_alarm
 *
 * Description:
 *   Sets/clears EXTI alarm interrupt.
 *
 * Parameters:
 *  - rising/falling edge: enables interrupt on rising/falling edget
 *  - event:  generate event when set
 *  - func:   when non-NULL, generate interrupt
 *
 * Returns:
 *   The previous value of the interrupt handler function pointer.  This
 *   value may, for example, be used to restore the previous handler when
 *   multiple handlers are used.
 *
 ****************************************************************************/

xcpt_t stm32_exti_alarm(bool risingedge, bool fallingedge, bool event, xcpt_t func)
{
	xcpt_t oldhandler;

	/* Get the previous GPIO IRQ handler; Save the new IRQ handler. */

	oldhandler = stm32_exti_callback;
	stm32_exti_callback = func;

	/* Install external interrupt handlers (if not already attached) */

	if (func) {
		irq_attach(STM32_IRQ_RTCALRM, stm32_exti_alarm_isr, NULL);
		up_enable_irq(STM32_IRQ_RTCALRM);
	} else {
		up_disable_irq(STM32_IRQ_RTCALRM);
	}

	/* Configure rising/falling edges */

	modifyreg32(STM32_EXTI_RTSR, risingedge ? 0 : EXTI_RTC_ALARM, risingedge ? EXTI_RTC_ALARM : 0);
	modifyreg32(STM32_EXTI_FTSR, fallingedge ? 0 : EXTI_RTC_ALARM, fallingedge ? EXTI_RTC_ALARM : 0);

	/* Enable Events and Interrupts */

	modifyreg32(STM32_EXTI_EMR, event ? 0 : EXTI_RTC_ALARM, event ? EXTI_RTC_ALARM : 0);
	modifyreg32(STM32_EXTI_IMR, func ? 0 : EXTI_RTC_ALARM, func ? EXTI_RTC_ALARM : 0);

	/* Return the old IRQ handler */

	return oldhandler;
}
